The are absolutely correct. Had an unsettling experience with a "sweet' lady in her 60s on a resort holiday being inappropriate with my 3 year old daughter last year. I think back now and in hindsight all the signs were there from our first day, but at the time, you try and not be judgemental, maybe she's just socially unaware of boundaries etc. As she never had kids we just assumed that's why she was smitten with ours.
She came with bags of dreamies to feed the cats the resort adopted. That was her hook. My daughter and her would feed the cats around the pool. Every day she would give a pack of dreamies to our daughter. On day two she had a 'gift' for our daughter in her room a few metres away and 'would she likes to come with her to get it' - still at this point we thought she was a safe, sweet old lady. They were gone for 3 mins but such a stupid, stupid thing to let happen and I'm so angry with myself. Throughout the holiday, we couldn't go anywhere without this lady appearing. Oddly, never interacting with our 3 month old baby, only the 3 year old.
My wife went for spa treatments daily and would bring 3 year old as the spa manager loved my daughter and would give her free mini-treatments. One day I forgot to take the nappy bag for the baby from her rucksack, so went to the spa to get it and found her upset. This sweet old lady had followed them into the spa reception. My daughter was talking about the chocolate wrap massage she was going to have when this woman starts touching her legs "oh, will they massage you like this or like this?" etc. My wife said she was discombobulated and couldn't quite compute what was happening. Spell was broken when she saw the look of horror on other guests faces. Then like the end of ' The Usual Suspects' we started piecing all our interactions with her together. So many red flags but only when they were all put together. Even husband who we didn't even realise she was with until well into holiday, never spoke a word, never interacted with us and would just sit in the background staring.
We felt like truly awful parents for assuming this sweet 'old' lady's was harmless.